As is known in the art, different wireless networks and/or systems of radios avoid interfering with each other by various options. For example, some systems rely on pre-arrangement or careful assignment of frequency bands, time slots, or signature pulses as is done for cellular systems through frequency reuse maps and time-division multiple access (TDMA) for Global System for Mobile Communications (GSM), orthogonal frequency-division multiple access (OFDMA) for Long-Term Evolution (LTE), spread spectrum for Interim Standard 95 (IS-95), and combinations of these for wideband code-division multiple access (WCDMA) through High-Speed Packet Access (HSPA) commercial cellular standards. Other systems utilize collision avoidance techniques such as those employed for a packet based systems such as 802.11/16/22 (WiFi and WiMax) where collisions are controlled as part of a multiple access medium access control procedure, e.g. carrier sense multiple access (CSMA). Still other systems utilize on the fly interference assessment and avoidance is used in the new, currently operational paradigm for “cognitive radio” via dynamic spectrum access (DSA) for the newly allowed “secondary” user (see IEEE SCC41: Standards for Dynamic Spectrum Access Networks). This is done by the system of “secondary user” radios actively sensing the radio spectrum and coordinating to choose an empty band for transmission. Such systems typically fail if they are unable to avoid interference.
As the consumer market continues to rise for smart phones and wireless data service, the demand for more and more throughput increases drastically and the radio spectrum continues to become more crowded. A new paradigm in wireless communication is emerging where radios can be built to withstand interference to the level where interference is no longer avoided. Interference is allowed, even invited, to allow for more wireless devices to make use of the scarce free space in the wireless spectrum. For example, the LTE Advanced standard (to support the Heterogeneous Network or HetNet feature) allows, even encourages, interference. If this new feature were enabled, reliable performance would require mobiles to have some kind of interference mitigation in the receivers.
A common idea for cognitive networks is to have them adapt at a network/routing layer, not the physical layer. A typically network may learn which nodes are having trouble sending and/or receiving packets and then adjust how packets are routed to avoid the troubled nodes. Here, the goal is not to invite or encourage interference, but rather on avoid using links that are hindered by interference.